drm/i915: make sure VDD AUX power has time to settle

When turning on or off the VDD AUX bit, we need to give the panel time
to start or stop or AUX transactions may fail.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 153a5934b2e1334757386e37c2abc107a771fbb5..bcd81f96fc7f3357bde6269b6b2bd2d12f50e3d0 100644 (file)
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -825,6 +825,7 @@ static void ironlake_edp_panel_vdd_on(struct drm_device *dev)
        pp |= EDP_FORCE_VDD;
        I915_WRITE(PCH_PP_CONTROL, pp);
        POSTING_READ(PCH_PP_CONTROL);
+       msleep(300);
 }
 
 static void ironlake_edp_panel_vdd_off(struct drm_device *dev)
@@ -836,6 +837,7 @@ static void ironlake_edp_panel_vdd_off(struct drm_device *dev)
        pp &= ~EDP_FORCE_VDD;
        I915_WRITE(PCH_PP_CONTROL, pp);
        POSTING_READ(PCH_PP_CONTROL);
+       msleep(300);
 }
 
 static void ironlake_edp_backlight_on (struct drm_device *dev)